Lead concentration profiles in the surface of lead crystal glass

Concentration profiles of lead in the surface of lead crystal glass (24 wt. %) treated by products of decomposition of ammonium chloride at 280 degrees C and 450 degrees C were measured by the method of photoelectron spectrosc opy. The concentration profiles showed that the dealkalization resulted in a distinct reduction of lead concentration in the glass surface already at the lower treatment temperature (280 degrees C). The dealkalized surfaces y ielded very low extracts of lead even by long-term leaching into 4 vol.% ac etic acid at room temperature.